Recently there has been developed a motorcycle equipped with an air bag device adapted to expand and spread upon detection of an impact to cushion the impact against a passenger. For example, JP-A No. 2005-153613 discloses a motorcycle equipped with an upper air bag device for the upper half of the body of a rider and a lower air bag device for the lower half of the rider's body. Further, JP-A No. 2006-218971 discloses an air bag jacket for wear of a passenger.